Valacyclovir in the Treatment of Herpes Simplex, Herpes Zoster, and other Viral Infections

Abstract

Background: Genital herpes and herpes labialis are prevalent, physically and pychologically painful, and often disabling. Herpes zoster is often very painful and may result in months or years of postherpetic neuralgia (PHN). Over the past two decades, the treatment of these conditions has been transformed by guanosine nucleoside antivirals such as valacyclovir (Valtrex®), a highly bioavailable prodrug of acyclovir (Zovirax®), and famciclovir (Famvir®), a highly bioavailable prodrug of penciclovir (Denavir®). Objective: We describe the pharmacology, pharmacokinetics, and clinical efficacy of valacyclovir for the treatment of herpes simplex, herpes zoster, and other viral infections. Valacyclovir is also compared with acyclovir and famciclovir. Methods: All published literature containing the word “valacyclovir” was reviewed and summarized. Results: Valacyclovir is the only oral antiviral agent approved for therapy of herpes labialis, the only antiviral drug approved for a 3-day course in the episodic treatment of recurrent genital herpes, as well as the only antiviral drug approved for once daily dosing for suppressive therapy. In herpes zoster, valacyclovir is more effective than acyclovir and equally effective as famciclovir at hastening the healing of zoster-associated pain and PHN. Conclusion: Valacyclovir is safe and effective in the therapy of patients with herpes simplex and herpes zoster and may be useful in other viral infections.